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Root sources of uncertainty are taken into account in a rigorous, systematic way.

Root Source Analysis (RoSA) is a systems-engineering methodology that has been developed at NASA over the past five years. It is designed to reduce costs, schedule, and technical risks by systematically examining critical assumptions and the state of the knowledge needed to bring to fruition the products that satisfy mission-driven requirements, as defined for each element of the Work (or Product) Breakdown Structure (WBS or PBS). This methodology is sometimes referred to as the ValuStream method, as inherent in the process is the linking and prioritizing of uncertainties arising from knowledge shortfalls directly to the customer’s mission driven requirements. RoSA and ValuStream are synonymous terms.

RoSA is not simply an alternate or improved method for identifying risks. It represents a paradigm shift. The emphasis is placed on identifying very specific knowledge shortfalls and assumptions that are the root sources of the risk (the “why”), rather than on assessing the WBS product(s) themselves (the “what”). In so doing RoSA looks forward to anticipate, identify, and prioritize knowledge shortfalls and assumptions that are likely to create significant uncertainties/risks (as compared to Root Cause Analysis, which is most often used to look back to discover what was not known, or was assumed, that caused the failure). Experience indicates that RoSA, with its primary focus on assumptions and the state of the underlying knowledge needed to define, design, build, verify, and operate the products, can identify critical risks that historically have been missed by the usual approaches (i.e., design review process and classical risk identification methods). Further, the methodology answers four critical questions for decision makers and risk managers:

What’s been included?

What’s been left out?

How has it been validated?

Has the real source of the uncertainty/risk been identified, i.e., is the perceived problem the real problem?

Users of the RoSA methodology have characterized it as a true “bottoms up” risk assessment. The insights gained regarding specific shortfalls (risks) in the underlying knowledge base are particularly important to decision makers in determining the readiness to proceed at major decisional milestones in the lifecycle of a program.

With RoSA the granularity of the assessment is taken to the level where one can see and assess the driving assumptions and state of the knowledge on which the program management and engineering rests, relative to specific customer-driven requirements. The methodology uses a knowledge matrix or grid.

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